Question

化简一个三角函数

（2cos^2α-1)/[2tan(π/4-α)sin^2(π/4+α)] 要具体过程

Answer 1

(2cos^2a-1)/[2tan(45度-a)*sin^2(45度+a)]
=cos2a/[2tan(45度-a)*cos^2(45度-a)]
=cos2a/[2sin(45度-a)*cos(45度-a)]
=cos2a/sin(90度-2a)
=cos2a/cos2a
=1